<template>
         <el-container class="home-container">
             <!-- 头部区域 -->
            <el-header>
                <div>
                    <img src="../assets/heima.png" alt="">
                    <span>电商后台管理系统</span>
                </div>
                <el-button type='info' @click="logout" >退出</el-button>
            </el-header>
            <!-- 页面主体区域 -->
            <el-container>
                <!-- 侧边栏 -->
                <el-aside :width="isCollapse ? '64px': '200px'">
                    <!-- 侧边栏菜单区域 -->
                    <el-menu background-color='#333744' text-color='#fff' 
                     active-text-color= '#379aff' unique-opend :collapse='isCollapse' :collapse-transition='false'
                     router :default-active='activePath'>
                     <div class="toggle-button" @click="toggleCollapse">|||</div>
                     <!-- 一级菜单 -->
                     <el-submenu :index="item.id + ''" v-for="item in menulist" :key='item.id' >
                         <!-- 一级菜单摸版区域 -->
                         <template slot="title">
                             <!-- 图标 -->
                             <i :class="iconObj[item.id]"></i>
                            <!-- 文本 -->
                            <span>{{item.authName}}</span>
                         </template>

                         <!-- 二级菜单 -->
                         <el-menu-item :index="'/' + subitem.path" v-for="subitem in item.children" :key='subitem.id'
                          @click="saveNavState('/' + subitem.path)">
                             <template slot="title">
                             <!-- 图标 -->
                             <i class="el-icon-menu"></i>
                            <!-- 文本 -->
                            <span>{{subitem.authName}}</span>
                         </template>
                         </el-menu-item>
                     </el-submenu>
                    </el-menu>
                </el-aside>

                <!-- 右侧内容主体 -->
                <el-main>
                    <!-- 路由站位符 -->
                    <router-view></router-view>
                </el-main>
            </el-container>
            </el-container>
</template>

<script>
export default {
        data() {  //左侧菜单渲染顺序
            return {
                menulist:[],  //左侧的菜单数据
                iconObj:{
                    '125':'iconfont icon-user',
                    '103':'iconfont icon-tijikongjian',
                    '101':'iconfont icon-shangpin',
                    '102':'iconfont icon-danju',
                    '145':'iconfont icon-baobiao'
                },
                isCollapse: false ,//判断是否折叠
                // 被激活的链接地址
                activePath:''
            }
        },
        created() {
            // 页面刚加载的时候立即获取左边的菜单
            this.getMenuList(),
            this.activePath = window.sessionStorage.getItem('activePath')
        },
        methods: {
            logout() {
                //清空token
                window.sessionStorage.clear()
                //重定向到登录页
                this.$router.push('/login')
            },
            // 获取所有的菜单
            async getMenuList() {
             const {data :res}  = await this.$http.get('menus')
            if(res.meta.status !== 200) return this.$message.error(res.meta.msg)
            this.menulist = res.data
           },
           //点击按钮 切换菜单的折叠与展开
           toggleCollapse() {
               this.isCollapse = !this.isCollapse
           },
           //保存链接的激活状态
           saveNavState(activePath) {
               window.sessionStorage.setItem('activePath',activePath)
               this.activePath = activePath
           }
        },
}
</script>

<style lang="less" scoped>
    .home-container {
        height: 100%;
    }
    .el-header {
        background-color: #373d41;
        display: flex;
        justify-content: space-between;
        padding-left: 0;
        align-items: center;
        color: #fff;
        font-size: 20px;
        > div {
            display: flex;
            align-items: center;
            span {
                margin-left: 15px;
            }
        }
    }
    .el-aside {
        background-color: #333744;
        .el-menu {
            border-right: 0;
        }
    }
    .el-main {
        background-color: #eaedf1;
    }
    .iconfont {
        margin-right: 10px;
    }
    .toggle-button {
        background-color: #4A5064;
        color: #fff;
        font-size: 10px;
        line-height: 24px;
        text-align: center;
        letter-spacing: 0.2em;
        cursor: pointer;
    }
</style>